Reactive armor - While there is no reason it couldn't exist in Star Wars, the weapons appear to be so catastrophically powerful that I doubt this would have any significant effect. I mean if you consider the power output of a turbolaser, it will be able to blast through the hull of a vessel with or without this layer.. Really seems un-necessary and bringing in elements of other Scifi into star wars. Also... "Lasers" in Star Wars are not thought to be "Light Amplification by Stimulated Emission of Radiation" weapons as they are thought of in the real world. The idea is that an X-Ray laser would have a higher frequency and a shorter wavelength, thus meaning higher energy output. Weaponised versions of these lasers require massively greater power sources than a normal laser (explosions from nuclear bombs have been used as the power for tests (which were inconclusive)).
So with the X-Ray laser I have a couple of issues I feel should be addressed.
1) They're not star wars technology.
2) From current indications, even if they are possible, then they are ridiculously impractical to use for military applications, resulting in a very low output for input ratio of energy. Meaning regular turbolasers would be more efficient in all likelihood.
3) I really don't think its a good idea to bring in non-star wars technology into the rp on anything more than a superficial level. There are literally thousands of star wars weapons of all different sorts.. it would be really nice to have something a little more tied to the canon.